Radar systems employ pulsed rf signals, commonly though not necessarily in the microwave frequencies, to determine the existence, location, range, velocity and direction of movement of various types of targets. In electronic warfare applications particularly, it is often desirable to be able to create new rf pulses from an original pulse or train of pulses. The newly created pulses may be employed to generate false targets, ghost images, jamming effects, and other information misleading to hostile radar. Radar simulation and training equipment may also employ the effects generated by controllable rf pulse multiplication.
Because the phase of the transmitted and received rf pulses is often a critical element in the detection and processing of radar images, radar receivers frequently use phase-locking local oscillators to perform coherent detection of the incoming rf pulses. Thus, it is desirable that multiplied rf pulses also maintain coherence with the original source rf pulses. Heretofore, detecting rf pulses from a source and reproducing coherently-related multiples of those pulses has required complex circuits to establish a phase reference with the source pulse(s) and generate new rf pulses with the proper phase and time relationships to the source pulse(s).
The present invention eliminates the need for complex detection or phase-locking circuits for coherent rf pulse multiplication. The coherent rf pulse multiplier herein disclosed enables the source rf pulse to replicate itself, without regeneration from another source. Coherence of the replicas with the source pulse(s) and with each other is a natural consequence of the apparatus, and requires no external circuits to accomplish.